The present invention relates to elevator doors systems and, in particular, to an elevator door system comprising a door that is wound upon a vertical axis during an opening operation.
Such elevator door systems are well known from the prior art and are described, for example, in WO-A2-2005/070807 and WO-A2-2005/070808. Each elevator door is generally formed from a stainless steel sheet or interconnected vertical rigid panels, typically manufactured from a metal. In operation, as the elevator door is opened and closed, the plurality of panels or sheet is wound onto and unwound from a vertical axis in the form of a motorized reel whereby the driving force from the motor is transmitted through the reel and onto the door to provide lateral movement thereof. Hence, not only does the door need sufficient strength to withstand a specific transverse force applied perpendicular to the plane of the door without exceeding the maximum permissible elastic deformation (as defined by regulations, see for example European Norm EN 81-1:1998 §8.6.7), but it must also be capable of withstanding the lateral driving forces transferred to it from the motor.
Furthermore, in the prior art elevator door systems discussed above the wrapping of the door in layers about the vertical axis can give rise to unwanted noise due to contact between the successive layers and continual winding and unwinding of the door about the reel may cause frictional contact between successive layers which may eventually cause damage to the aesthetic appearance of the door.
FR-A-2664324 discloses a shutter system used to open and close a horizontal opening. A motor acts on a roller to feed out the shutter under compression to close the opening. A continuous or discontinuous belt of hook and loop fastening means (Velcro™) is provided at each end of the shutter to ensure that each panel of the shutter is positioned correctly within the guide channels and to reduce friction therebetween. The Velcro™ belts also ensure that the shutter is tightly wrapped around the roller in the fully opened position. As the Velcro™ belts cannot transmit compressive force, the shutter system of FR-A-2664324 suffers from the same disadvantage of the prior art mentioned above in that it must be capable of withstanding the compressive lateral driving forces transferred to it from the motor.